I personally have not dealt with this vendor but I give you a few pointers on what to look for when purchasing a server.

** How long is the warranty?

** What type of design will you want (Tower or Rackmount)

** What kind of support program do they offer.

These are basic things to have in mind, even if you will be maintaining the servers yourself. The warranty/support program might cover damaged harddrives (it happens!) or other physica components and save you some money if this would happen.